Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bioreactor boosts chemical fermentation by 50 percent: study

30.03.2004


A device invented at Ohio State University has dramatically boosted the production of a chemical that performs tasks as diverse as scenting perfume and flavoring Swiss cheese.


Shang-Tian Yang



Engineers here have used their patented fibrous-bed bioreactor to genetically alter a bacterium so that it produces 50 percent more of the chemical propionic acid than the organism produces normally. And it did so without the aid of chemical additives employed in industry.

The device also reduced the amount of two unwanted byproducts that normally result from propionic acid fermentation -- cutting one byproduct by more than half, said Shang-Tian Yang, professor of chemical engineering at Ohio State.


The bioreactor grows cells inside a bundle of fibers. Yang and his colleagues have previously shown that they could control the growth and differentiation of cells by changing the packing density of the fibers in the bioreactor.

Monday at the national meeting of the American Chemical Society in Anaheim, Yang and doctoral student Supaporn Suwannakham reported that they were able to produce 72 grams of propionic acid per liter of sugar solution inside the bioreactor. Traditional fermentation typically yields only 50 grams per liter or less, making the new process 44 percent more effective.

More important to Yang is the fact that he and his team were able to coax the bacterium P. acidipropionici to make more acid without adding chemicals to the mix. They simply immobilized the cells on the fibers so the cells could grow and evolve -- or mutate -- in a harsh environment.

“Most labs focus on mixing the right chemical or biological cocktail to grow cells,” he said. “We are the only group that I know of that is working to optimize the cells’ physical environment.”

The bioreactor can grow cells for a variety of applications including fermentation, animal cell culture, tissue engineering, and waste water treatment. Since 1998, Yang and his colleagues have used the device to make large quantities of a protein -- Developmental Endothelial Locus-1 Protein -- for cancer research. A commercial company recently licensed the technology for agricultural applications.

Yang designed the bioreactor as a three-dimensional alternative to the flat petri dishes and trays that scientists traditionally use to culture cells. The fibers anchor living cells in place as they grow and reproduce.

For this latest study, the engineers grew P. acidipropionici in a sugar solution, and gradually adjusted the sugar concentration so the cells would tolerate -- and produce -- higher concentrations of propionic acid. Tests yielded an average of 72 grams of the acid per liter. The bioreactor also produced 52 percent less succinate and 14 percent less acetate -- two chemicals that industry normally has to remove from the fermentation mix before the propionic acid can be used.

When Yang and Suwannakham examined the cells from the bioreactor, they found that the cells had mutated and changed several key enzyme activities. Production of enzymes for propionic acid formation had increased, and the enzyme for succinate production had decreased.

Aside from giving Swiss cheese its characteristic smell and flavor, propionic acid is often used as a preservative and flavor enhancer for a wide variety of cheeses and baked goods.

In the chemical industries, it’s used as an ingredient for dyes, perfumes, pharmaceuticals, herbicides, rubber, and plastic.

With today’s growing emphasis on organic or “all-natural” products, Yang sees a market for propionic acid made without chemical additives in the bioreactor. “A company could conceivably market a product as being made with ‘all-natural’ propionic acid,” he said.



Contact: Shang-Tian Yang, (614) 292-6611; Yang.15@osu.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu

Pam Frost Gorder | Ohio State University
Further information:
http://researchnews.osu.edu/archive/propacid.htm

More articles from Life Sciences:

nachricht For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)

nachricht New method to rapidly map the 'social networks' of proteins
27.06.2017 | Salk Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>